Generator Sizing

Sizing a Generator

To determine the size of the generator needed, total the rated watts of the appliances and fixtures you’ll want to operate during an outage. Some loads are easy to determine -- a 100-watt light bulb, for example, uses 100 watts. Ten 100 bulbs would require 1,000 watts, or 1 kilowatt (KW). The power requirements for appliances are often provided in the operating manual. These specifications are also stamped on the “face plate” along with serial and model numbers.

Manual and Automatic Start Generators

Generators come in two basic configurations -- manual or automatic start. Manual start systems enable users to get by with smaller generators, provided that all equipment is not restarted at the same time.

After a power failure, disconnect all equipment. Once the standby generator is running, restart motors one at a time beginning with the largest motor. This procedure reduces needed power. Since the extra start-up power is not necessary while equipment is running, power for other equipment- such as lamps and appliances- is available.

Generators and Carbon Monoxide

Poisoning from CO (carbon monoxide) is a very common and very serious accident that can happen if generators are used improperly. Every proper precaution should be taken as it is a very serious danger. Portable generators should never be used indoors. This includes: basements, crawl spaces, garages, carports, and any other imaginable enclosed or partially enclosed space. They should not be used near open windows or inlets that may allow for exhaust fumes to leak in. CO is odorless, and invisible.